Orpheus Beaumont was named after New Zealand's worst shipwreck. When she was born, her mother was grieving for Orpheus' teenage brother - presumed drowned in the disaster. Later it was Orpheus' turn to mourn when another brother was taken by the sea off the Otago Coast.

The daughter of a sea captain and then married to one, Orpheus was sensitive to the threat that the ocean posed to human life.

So much so, that she invented a life jacket.

Her "Salvus" was made by the tens of thousands and won the approval of the safety experts of the British Board of Trade.

"It was a sense of, 'I'm going to beat the sea' - it was her chance to help in the struggle against the sea," explained her great-granddaughter, Caroline Fitzgerald, of Dunedin.

On February 7, Ms Fitzgerald will join other descendants of the crew of HMS Orpheus in Auckland for a commemoration of the vessel's loss on the Manukau Harbour Bar, on February 7, 1863.

Out of 259 men on board the corvette, 189 men were drowned at the treacherous west coast harbour entrance.

Ms Fitzgerald said it was not until 12 years ago that she learned the story of her great grandmother, who came from the Channel Islands, in the English Channel, and whose maiden name was Newman.

"She was named after the shipwreck, because her brother Henry Newman was on it and he was supposedly one of the drowned.

"Her mother was pregnant while grieving for him and this little girl grew up believing she was possessed by the drowned souls, so much that she had drowning fits.

"Her mother felt guilty.

"In Victorian days it was believed you would imprint on to your children your thoughts and emotions during pregnancy."

While Orpheus was a toddler, the family learned that Henry had not perished on the Manukau Bar.

The 18-year-old was returned to England and on leaving the Royal Navy emigrated to New Zealand and settled in Invercargill.

Widowed in 1870 in Jersey, the mother brought her three youngest, including Orpheus, to settle in Dunedin.

When Orpheus wed a mariner, she went on voyages to tropical islands where she saw the amazing flotation qualities of a waxy fluff harvested from the seed pod of the kapok tree.

Two tragic events in 1912 turned this knowledge into fuel for an inventive mind and a compulsion to save lives.

That year, her fisherman brother William drowned out of Port Chalmers.

On April 15, the world was shocked by the sinking of the liner RMS Titanic after it hit an iceberg on a transatlantic voyage to New York, and the death toll of more than 1500 people out of 2224 passengers and crew.

Since the mid-19th century, cork was the buoyant material favoured for use in life jackets.

But in the wake of the Titanic disaster and inquiry, a call went out for improved life saving aids.

Ms Fitzgerald said Orpheus found an answer to the hard cork ramming into the neck when someone jumped off a ship.

She invented a Bolero-style jacket made out of linen canvas, which was advertised as "fool proof".

It could be worn by an adult, woman or a child and, if put on in a panic, could be worn back to front or upside down - and still do its job.

The secret of its buoyancy was sealed chambers, stuffed with kapok - able to float 15 times its weight.

There was much correspondence between Orpheus in Dunedin and the British Board of Trade representatives in Australia.

But she would not be knocked back. For every fault the experts found with the prototype, she willingly improved it.

Finally, on the last day of World War I on November 11, 1918, her Salvus jacket was accepted by the British authorities.

Her first order was 30,000 for the Military Sea Transport at Home. The jacket was also supplied to English ferries, the Union Steam Ship Co fleet and the New Zealand interisland ferries.

It was used world-wide but during World War II it was superseded by other inventors' versions, such as the yellow inflatable "Mae West" jackets, and those made of synthetic materials and modified to give support for the head.

Orpheus died in 1951, aged 85, leaving a daughter, Constance, and a son Llewellyn. He served in the army during World War I and despite injury helped his mother by being the model for the instructions for wearing the Salvus.

Ms Fitzgerald, aged 48, edited two books of letters by another set of her great-grandparents, who were missionaries: Te Wiremu - Henry Williams, Early Years in the North; and Letters from the Bay of Islands: The Story of Marianne Williams.

She said her research on Orpheus Beaumont led her to Otago University to do her second masters degree. It is in science communication, with natural history documentary film making.

In a joint project with fellow student Fiona Grundmann, a 25-minute film called The Drowning Season, has the Orpheus disaster setting the scene for 150 years of lives lost but for want of a flotation aid.

"For me, the emphasis is on the humble life jacket - when we get on a boat we have to decide whether to put it on or not."

"A majority of those boys and men on the Orpheus had never been to sea before that voyage from Australia.